Method of and apparatus for starting vapor devices.



P. H. THOMAS. METHOD OF AND APPARATUS FOR STARTING VAPOR DEVICES. APPLICATION FILED 13316.24, 1906.

1,1 10,591, Patented Sept. 15,1914-t.

P. H. THOMAS. METHOD OF AND APPARATUS FOR STARTING VAPOR DEVICES.

APPLICATION IILBD DEO.24, 1906.

1,1 10,591. Patented Sept. 15, 1914.

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rnncv n; THOMAS, or "MONTCLAIR, new .annsiiv, ASSIGNOR, BY Imsnn ASSIGN- MENTS, To coornn HEWITT ELECTRIC commm', or nonoxmr, NEW .mnsnv, A

CORPORATION OF JERSEY.

memory or am) APPARATUS roe STARTING vnron DEVICES.

Specification of Letters Patent.

Patented Sept. 15, 1914.

Application filed December 24, 1808. Serial No. 349,270.

To all whom it may concern Be it known that I, Pnnor H. THOMAS, a citizen of the United States, and resident of Montclair, county of Essex, State of New Jersey, have invented certain new and useful Improvements in Methods of and Apparatus for Starting Vapor Devlces, of which the following is a specification.

My present invention relatesto methods and means for starting lamps and other vapor devices, particularly the mercury vapor devices of the Cooper Hewitt type. I

The object of the invention is .to provide an eflicient starting means having certain advantages, among which may be mentioned, freedom from the complications necessarily involved in tilting the lamp whether performed automatically or by hand; and quickness and certainty of operation without sacrifice of any of the advantages appertaining to methods and apparatus heretofore employed by others, as, for instance, to those set forth in the Hewitt and Rogers application, Ser. No. 52,499, filed March 23rd. 1901, and Hewitt application, Ser. No. 211,07 9, filed June 3rd, 1904.

In the type of devices to which this invention is applicable, the starting operation involves breaking down the negative electrode starting resistance as well as breaking down the nonconducting quality or condi tion of the vapor column between the main electrodes, and my present invention contemplates establishing an initial current regularly operating between the main negative electrode and a supplemental positive electrode and then transferring the current flow to the main positive electrode, using, if necessary, an accelerated potential to facilitate or insure the transfer. The negative electrode resistance to starting, is overcome by separating current-carrying electrodes within the vacuum in such a manner as to establish current flow through the vapor into the negative electrode so that it no longer has nega ive electrode resistance to starting. This initial flow of current is established through a supplemental positive electrode preferably normally in contact with the main negative electrode, by passing current initially through a shunt circuit containing a current shifting device. The electrodes are ative movement thus establishing current flow through a short column of vapor. The current shifting device may be and preferably 1s a mercury vapor apparatus having the general characteristics of Cooper Hewitt vaporconductors, but so proportioned and so connected to related circuits including an operating inductance, that when the starting current is thrown through its vaporpath, sald shifting device is unable to maintain such flow of current continuously, but soon ceases to operate, thereby causing the induct'ance to develop the accelerated voltage desirable for causing or facilitating current flow between the main operating negative electrode of the lamp or device to be started and the normal or main positive electrode thereof. Other-devices for suddenly interrupting flow of current through this path may be employed, but the vapor conductor device is peculiarly adapted for the purpose.

Referring to the drawings, Figures 1, 2, 3, 4, 7, and .8 are diagrammatic views indicating various ways in which my invention may be practised, and Figs. 5 and 6 are details of current shifting devices which may be employed.

The vapor device 1, which may be a lamp used for the purposes of illumination, is suitably supported in any desired position, I

preferably horizontally or else with the 'positive electrode 2 located above the level of the main electrode 3, the latter consisting preferably of mercury. The main terminals 4 and 5 are connected with the supply circuit through conductors 6 and 7. The envelop is preferably glass and hermetically sealed after having been cleansed of all foreign gases and gas producing substances.

Adjacent the negative electrode is arranged an auxiliary electrode 8, which is adapted to make and break contact with said negative electrode, the relative movement necessary for this purpose being preferably caused by magnet 9, which may operate to rotate the lamp upon its longitudinal axis, and. thus move the mercury in 0 or out of contact with the auxiliary electrode 8, or it may operater directly upon the auxiliary positive electrode within the lamp. In the' latter case this electrode 8 will be formed of or provided with magnetic material and adapted for movement to or from the n1ervapor device 1 and said shifting device 13,

v cury. To thisend it may be made of flexible suitable or desired type.

The current shifting'device 13 may be an oil switch or a vacuum break or any type capable of giving sufliciently sharp interruption of current flow. This should be of such .a'nature as will cause the inductance coil 9 to furnish the desired acceleration of electrical pressure for facilitating or insuring the'transfer of current flowfrom. its short vapor path, between the main negative electrode 3 and the supplemental positive electrode 8, to the longer path, between the main negative electrode 3 and the main positive 2.

The movement necessary to open the metallic connection and interpose the vapor path in the shifting device 13 may be imparted either by hand .or by the magnet 9 or by a mechanical connection between the whereby when the former is rotated on its "axis the latter will also be moved to open the metallic circuit. As shown in Fig. 1, the shifting device 13 is a device of the Cooper Hewitt type, preferably specially designed and of relative small size, wherein the circuit is made and broken between a solid positive terminal 14 and a negative liquid terminal 15, preferably of mercury.

In the operation of this device, the circuit is closed from the source through the lead 6 and shunt path 11. It flows through the resistance 12; thence through the positive electrode 14 and mercury 15 of the current shifting device 13; thence to auxiliary terminal l0, and through auxiliary electrode 8, main negative electrode 3, and main terminal 5 of the main operating vapor device, and finally through magnet 9 and conductor 7,'to the'so-urce. Theflow of current through this path energizes the magnet 9, thus producing relative movement of main negative electrode 3 and auxiliary positive electrode 8, either by rotating the lamp on its longitudinal axis, orby direct attraction upon the magnetic material of the auxiliary positive electrode 8. The negative electrode starting reluctance of the negative electrode 3, being thus broken down by the flow of current through the short gap between ,3 and 8, one of the main factors opposing the starting of the lamp has been eliminated. The flow of current through this path generates heat and vapor within the envelop, thus modifying the condition of the vapor column between the main electrodes.

The relative movement which causes the starting of the main negative electrode, may be utilized to break the physical metallic contact between the electrodes 15 and 14 of the shifting device. This device has such characteristics of volume, density, heat radiating capacity, etc., that it has an irregularly varying opposition or resistance to the current, and also an irregularly varying critical operating voltage below which it becomes a nonconductor. These irregular variations are particularly marked when the vapor device is cold. The resistances of the circuit, as at 12 and at the negative electrode 3, are such-as to limit the energy flow-v ing in the shunt circuit down to values approximating those which are critical to the operation of the lamp. The ordinary flickering or abrupt variations characteristic of the phenomena normally observed in the shifting region orpoint where the current enters the negative electrode, may produce a sufiiciently accelerated potential from the reactance to effect starting of the main -vapor device. In general,'however, the combined resistance includin the flickering at the negative electrode 0 the shifting device, will be sutlicient to interrupt completely the current flow therein. In any of the described arrangements, the interruption of the circuit at 13 involves interrup tion of the circuit at the gap between 3 and 8, and such sudden interruption of flow inthe shunt path, causes an acceleration of potential from 9 to impose a breaking down stress upon the nonconducting column between 3 and 2 whereby a flow ofcurrent is initiated between them and the device is thus started. It will be obvious that if for any reason the circuit breaks within the lamp at the gap between 3 and 8, the result will be the same.

The shifting device 13 may be connected so that the vaporizable element, such as" mercury, is thenegative electrode, but, if desired, the connections may 'be reversed so that the solid electrode is the negative electrode.

; .If desired, the current shifting device may be operated by a second magnet separate, from that used to effect the opening of the circuit between the main negative electrode 3 and the auxiliary positive electrode '8. y

This is indicated in Fig. 2 wherein the parts are not materially different from those indicated in Fig. 1, except that the mercury electrode and the separation of the electrodes is effected by magnet 9, which is inv i cluded in a shunt across main terminal 5, and auxiliary terminal. 10. It will be 'ob-.-- vious that in the operation of this device the magnet 9 effects relative movement and uau:

' separation of electrodes Sand 8 by relative movement thereof, in either of the ways previously described. The increase of re sistance due to the interposition of the active'w negative'electrode in place of" the physical metallic contact between 3 and 8, will result in an increase of current flow through the shunt path of the magnet 9, thereby energizing the same sufficiently to open the circuit of the current shifting device 13 by bodily tilting the device and thus shifting the mer cury terminal 15 after the manner described in connection with Fig. 1. The starting apparatus may be completely or partially self restoring, as may be found desirable. Where the separation of electrodes 3 and 8 is effected by attraction'of magnet 9, operating to draw the latter away from the former, the electrode 8 may be arranged to drop back into contact with the mercury 3 as soon as the magnet 9 isdeenergized.

The current shifting device 13 is prefer ably mounted upon trunnions 16, and may be arranged to remain in the position it is placed'so that the metallic contact ofclectrodes 14 and 15 will remain either closed or open until changed by the operator. In

such case the apparatus may be started by positive manual movement of said shifting device to bring the electrodes into and out of contact, said movement being eflected by hand of the operator, either applied directly or through suitable intermediate devices. If the device 13 is provided with a self-restoring electrode at 14:, Fig. 2, the latter may be arranged to come back into contact with the mercury as soon as the magnet 9 is deenergized. If, however, the magnet 9' is employed to tilt the device 13 by rotary movement about the trunnions 16, a spring 17, or equivalent means, may be employed to efiect movement in the opposite direction to. restore the contact between 14 and 15. If the magnet 9 is utilized to rotate the entire device about its longitudinal axis to cause separation of electrode 3 and 8 by shifting of the position of the mercury, the

I restoration may be efiected by a spring or equivalent means, and the rotary movement of the device'l in both directions may be caused to impart suitable corresponding -movement to the shifting devicel3 through simple link and lever connections. In any case where the connections between the electrodes 3 and 8 of the main device and the electrodes of the shifting device, are

made self restoring upon cessation of current flow, the device will begcompletely self restoring and automatic in its action. If the lamp goes out for any reason, as, for instance, intentional interruption of the circuit thereof or accidental fluctuations of pressure of the supply circuit, the magnet 9 and also the magnet 9, if used, will become same time weurrent'iflows through shunt branch 21 and magnet 22, thereby tilting the' shifting device -'13 andf'interposing the vapor path inf-'ithe-circuit thereof; The 0p 1 eration then as 2, except I that as soon as the current news between themain positive 2 and- ;'m'ai1i negative '3," the shunt magnets .9 'and 22 may be short circuited and deenergized so that the electrode 8 and shifting device :13 are both'auto matically restored to normal; closed position, as by the force .of-gravit'y a ainst which they must then be raised by t emag'nets 9' and 22, which is :the construction 'shownn Such immediate, self restoringaction at both breaks, closes .the shunt circuit around the lamp, and would "result inmomentarily-- putting it out of operation" and thenrestormg 1t. In order toavoid repeated inter-' mittent action of this kind, I may employ an automatic cut-out for the shunt circuit,

energized by a coil in the main circuit of the lamp. I-have shown such a-cut-out-arranged in the circuit'of- Fig. 3,-andit will Y be understood that such devicemay' befap plied to the circuitsof Figs. 1 and 2. As soon as the lamp starts, the magnet 39 is energized and the entire shunt path is broken, by opening the same at 40, and the lamp continues to operate with the parts thus disposed. If, however, the lamp goes out for any reason, as, for instance, intentional interruption of the circuit thereof or accidental fluctuations of the supply, the" automatic switch 40 closes the shunt circuit, again placing theapparatus'in condition to described; If the conditions "causing the lamp to go out are but momentaryfit will be automatically restarted at once. If the conditions persist, as wherethe switch. 18 has been opened purposely,the apparatus will be restored to condition for automatically restarting the lamp and such operation will be efl'ectedimmediately upon closure of the switch.

The arrangement shown in Fig. 4'diifers from the preceding in certain aspects. It is provided with a cut-out 39 and 40 as in the device-of Fig. 3. The device 13 is a vacuum circuit breaker having'solid electrodes. The electrode 8 is of flexible material and norperform the cycle of operations first above mally held by its own elasticity out of con tact with the liquid electrode,'bein'g drawn; into contact with the'same by the magnet 19, corresponding to magnet 9. Magnets 19and 'iso I 13 -The jnecessar .22 are in parallel with each other, but' are' connected in shunt across the-main negative electrode .3 and the auxiliary positive electrode 8'. The magnet 22 is considerably more sluggish than themagnet .19, so that the vacuum circuit breaker 13- is not tilted to openthe circuituntil after the magnet 19 has operated. The operation of the magnet 19 is caused by passageof current through 10 -;the,device 13..when in its normal closed position; It draws theelectrode 8. into contact with the mercury 3, and being thus short circuited looses its attractive .force and the ele'ctrodeyB springs back, thus starting our- 15mm floWbetw'eenitself and the mercury 3..

f jThe cir-cuiti ofmagnet'22 and the win of-=.sai d. ;magnetpareiso designed 1 that said magnet will be able to tiltthefdevice 13',

evenwith the amount of currentqflowing ;thL-Qthr01lgh after the .current has beenv startd'through the path between 3 and 8'.

' Theacut-out 39, 40,;in this system, as in that of.-;l .ig. -3,,acts as soon as the lamp'is started byg'flowjof current .through the main elecr" v 25,:f1trodes, the, latter'resulting from the shock I" due tdbreak of the shunt circuit through 'mavbe furnished y the magnets 9. and 22, on by aflseparate coil in'conductor 7.

I to ..It,-will beunderstood that the amount of resistance. at. 1 ;2..is predetermined or adjusted with .respect ,.to-the characteristics of the 'Ishifting' device 13 to cut down the current flowing through the latter to a point where 3551f. will notv operatestea'dily and continuously,

but will be ina sensitive, critical state, where the. variations of resistance to which I have referred will be sufficient to cause it to lose its conducting quality and thereby interrupt 40 .such shunt circuit. In some instances I have noted that the abrupt fluctuations of tween the main terminals, the resistance.

through such main .path immediately be comes so. low as to short circuit the shifting device 13 and thereby cause the-vapor gap therein to be restored to the nonconducting condition. y I

. Theshifting device 13 operates to produce a very sudden interruption of the shunt circuit at a point outside of the vapor device to bev started, and said shifting device 13 need be no larger than is necessary for this purpose. It may be very small in comparison with the size-of the vapor device 1, in

some instances being not more than a few' nches long. Thus 1 1t may be very. coninductance in this case ia iopar veniently assembled with the other operating parts, in a compact form well adapted for practical use. It is comparatively 1nexpensive.

It is sometimes desirable to-make both electrodes of the shifting device 13 ofsolid material, in which case the device may take the form shown in Fig. 5, where the vacuated inclosure 4:1 is formed with trunnions 42 and 43, and provided with a movable electrode 44, hinged to the terminal 45, as. shown at 46. Cooperating with this is a relatively fixed electrode 47, extending trans- A versely of the path of movement of said movable electrode 44, and connected to the.

. other terminal 48.

In Fig. 6 I have shown a current shiftingdevice having both operating terminals of liquid mater1al,"'ipreferably mercury. The device consists -o a glass case 53 provided with trunnions 54-..and-. 55, and formed with two depressions or cavities '56 and 57, separated by the ridge 158 serving the function of a partition to separate the :twobodies of liquid. From. points diametrically opposite 9 )9 each of said depressions, the walls-of the vessel are carried in diametrically;across the same into a point; near the bottom of said receptacles 56 and 5'7...- Conductors 59 are connected to leading in-wires .60, sealed into 1 the ends of the sameyandcoming. intocontact with the liquid mercury. 'In operation of the device to makeand break the-circuit,.. it is rotated about the trunnions Stand 55 as an axis, thereby causing the mercury tolog.

bridge across one end of the elevation or partition 58 and upon a reverse movement,,- the bodies of mercury are separated. If the current is impressed on they conductors 59 and 59 at this. time, it will be made and v construction and of operation, both mechanical and electrical. In this device the separation of the main negative electrode and the supplemental positive starting electrode is efie'cted by rotation of the lamp about its longitudinal axis, thereby causing the mer- 11-5 cury of the negative electrode to flow. into and out of contact with the supplemental positive electrode. As shown. these electrodes are adapted to be normally in contact and to be moved out of contact. During the operation of the device, they are preferably normally held out .of contact. The vapor electric device in this case isused asa lamp, and is shown in a horizontal position. This position is very desirable where the lamp "is used for light giving purposes, and has been discovered by us to be practicable where the lamp is provided with a condensing chamber adjacent the negative electrode as shown.

The positive electrode seemsto maintain 1,130

1 mur high temperature in the remote portions of the tube, so that practically'all condensationf is determined 'in said condensin chamber, where it falls directly back into the body of mercury constituting the main negative electrode. In said figures the apparatus is mounted in a suitable support, comprising a chamber 30, suspended by pipe ,31, and 1n closing the auxiliary partsof the apparatus. Extending from said chamber are tubular supports 32, 33 terminating in depending suspension devices 34- and 37. The latter terminate. respectively in strapsor openings 35, 38, movably but securely engaging extensions 36, 39, said extensions being preferably made integral with the lamp tube. The auxiliary operating mechanismis contained in thechamber 30, and comprises a ballast 40. of any ordinary or desired type, a resistance 12, an operating electromagnet. 9, and a current shifting device 13*, said parts being connected up and operating in a. manner hereinafter described. The lamp being rota tably mounted, as described, is preferably normally in the position shown in Fig. 8, with the supplemental positive electrode in contact with the mercury, the separation being caused by movement about the longitudinal axis of the lamp to the position shown in Fig. 7. The ballast 40 is arranged in series with the lead to the posifive electrode 2, from which the circuit, during the normal operation of the lamp, is completed through the main vapor column 1*, negative electrode 3, and negative lead 7. In the main negative lead is serially ar ranged the operating electromagnet 9*, which performs several functions. It serves as a starting inductance for furnishing the accelerated potential for efi'ecting the transfer of the path of current flow from the supplemental ositive electrode path to the main posit ve electrode path; also as a .steadying inductance to prevent unsteadiness of operation of the lamp, and, finally,

. as a source of power for efl'ecting the necessary mechanical movement of the movable parts, through movement of the armature 41. The movement of the armature 41 serves to rotate the lamp about its longitudinal axis to separate the starting electrodes and also to rotate the current shifting device 13 to separate the electrodes thereof. The movement of the armatureis applied to effect this purpose by any desired mechanism, as for instance, by a link 42, connected to a lever 43, pivoted at 44, and connected by 45, with lever arm 46, secured to the lamp by ring 47, encircling the same. The lever 43 is also pivotally connected to link 48, which is in turn pivoted to an arm 49 entending from the current shifting device 13*. The device 13 may be of any of those previously described, but. as shown in the rawing, is of the form illustrated in Figs.

turne on, it flows through this shunt path and energizes the magnet 9, which attracts the armature 41,. thereby rotatin the lamp to the position shown in Fig. 7, t us causing an initlal flow of current from the auxiliary ositive 8 into the main negative electrode It also rotates the current shifting demore 13, the relation of parts being such that the circuit is broken in 135after'8 and 3 have been separated and current flow from the former into the latter has been initlated. The flow of current into 3 breaks down. the negative electrode reluctance to startin and subsequent separation of the .electro' es of 13*, causes an accelerated potential developed in the winding 9*, to be impressed u on the main electrodes of the lamp, there y causing a breaking down stress and consequent flow of current from the main positive electrode 2* through the main vapor column of the lamp to the main negative electrode 3. The electromagnet 9 being in series with the main negative lead, remains energized during the operation of the lamp and serves to maintain the parts in the position described, as long as current flowsbetween the main electrodes of the lamp. The weight of the armature, assisted by a spring or other auxiliary means, serves to restore the parts to the initial position shown in Fig. 8 as soon as current ceases to flow and said magnet 9 is denergized.

It will be understood that the practical outfit described above may be modified so as to embody any of the principles of operation hereinbefore described with respect to Figs.

1, 2, 3, 4, and 6 of the drawings.

In all arrangements shown herein, the arrangement of parts may be such that separation of the main negative electrode and the supplemental positive electrode within the lamp, takes place either before or after the separation of the electrodes in the current shifting device. It will be found in practice, however, that where a solid negative electrode is used in the current shifting device, as in Fig. 5, it is preferable to have the separation occur within the lamp before the electrodes of the shifting device are separated, because the solid negative electrode is not so well adapted to sustain a considerable current for any length of time. If the negative, electrode of the shifting device isof mercury, or if both of the electrodes of shifting device are 7 Q ,mercnry, as, por in- "having-main electrodes and a sup-j ple'nie "electrode adjecenta ma n elec-' ma a-main circuit forsaid mam electrodes, and a coil in said circuit, in combn nation: with a circuit in shunt around a. main electrode and a rtion or th'efv'apor column of said device, at in series; with said sup ..plemental electrode, with said adjacent mam electrode. and coil; anda switch in said shunt mcircuit. J ,1 I

.15. :A vapor electricdevice 'of the class described, having main electrodes and a. supplemental electrode adjacent a ma n electrodeya main circuit for said main electrodes, and a coil in said circuit, in eomb1nation with a circuit in shunt around amain -.electrode and a portion of the vapor column of said'device, but in series with said supplemental. electrode, with said ad acent mainelectrode and said coil; and a switch in .said shunt circuit operating to open said shunt circuit automatically whenever current flows therein. 16. A vapor electric device of the class described, having main electrodes one being snegative electrode and a movable supplemental positive electrode adjacent said mam negative le'l'ectrode and normally contacting A therewith, and a coil in series with both said main electrodes for separating said supple mental electrode and mainnegativeelec-' trode, in combination with a circuit in shunt varound a main positive electrode and a portion of the vapor column of said device, but in series with said supplemental electrode, with said adjacent main negative electrode and saidcoil; and a switch in said shunt circuit operating to open said shunt circuit automatically whenever current flows.

17. A vapor electric device of the class described, having main electrodes one being a negative electrode and a movable supplemental positive electrode adjacent said main negative electrode and normally contacting therewith; and a coil in series with both said main electrodes for separating said supplemental electrode and main. negative electrode, in combination with a circuit in shunt around a main positive electrode and a portion of the vapor column of said device, but in series with said supplemental electrode, with said adj acent main electrode and said coil, and a switch operating to open said shunt circuit automatically whenever currentflows.

18. A vapor electric device of the class 4 described, having main electrodes one being a negative-electrode and a movable supple-' mental positiveelectrode adjacent said main negative electrode and normally contacting therewith; and acoil in series with both said main electrodes for separating said supplemental electrode and main negative electrode,.in combination with a circuit in shunt electrode, combination with a self-restoring circuit 1 breaker in said circuit and an automatic cut-out operating to. open said circuit when said first mentioned vapor device is in LOPGI'itfilOII. z

connected to serve as a starting inductance around a main positive electrode and" a'portion of the vapor column of said device, but

and said coil; and a second vapor device'in-"70 said shunt circuit operating to open the same automaticallywhenever current flows therein.

19. A vapor electric device of the class described, having main electrodes and supplemental means for impairing the electrode reluctance to starting at the negative electrode, a main circuit and a coil in said circuit, in combination with a circuit in shunt around a main electrode and a portion of the main vapor path through said device, but in series with said coil; and a second vapor device, interposed in said shunt circuit, normally closing, but operating to open said shunt circuit automatically when current. flows therein.

. 20. A vapor electric apparatus of the class described, having a supplemental positive electrode, means for moving said electrode into and out of contact with the negative and a circuit for said means, in

21. A vapor electric device and means for starting the same including a shunt circuit, current shifting device, and a supplemental positive electrode for impairing the negative electrode reluctance to starting, in combination with an electromagnet in series with' said vapor device and with said shunt circuit, said electromagnet being designed and for starting the lamp, as a steadying inductance for keeping it alive when started, and as a motorfor effecting the necessary movement of the movable parts. 22. A vapor electric device and means for starting the same, including a shunt circuit,

current shifting device, and a supplemental positive electrode adjacent a main negative electrode for breaking down the negative electrode reluctance to starting, in combination with an electromagnet in series with said vapor device and with said shunt circuit, said electromagnet being designed and connected to furnish the necessary inductance for starting the lamp and for keeping it alive when started; and to serve as a motor for relatively moving the supplemental and main negative starting electrode.

23. A vapor electric device and means for starting the same, including a shunt circuit, 125 current shifting device, and a supplemental 1 positive electrode adjacent a main negative electrode for breaking down the negative electrode reluctance to starting, in combination with an electromagnet in series with 130 sa'dv; fapor 'device and with said shunt circu1t,-sa1d electromagnet-being designed and connected to furnish the necessary inductance stor-starting the lamp and for keeping it '5 :alive when started; and to serve as a motor for relatively moving the supplementaland :main negative starting electrodes and for movin said circuit shifting device.

24.'- n an electric lighting apparatus, a

' 10 .vaporelectric 1am comprising an elongated --:.-glass tube, forine with a cavity containing liquid 'mercur and'withan enlarged con- I densing cham er adjacent the latter, asuptiiple'mental positive electrodenormallyinconlfii tact with said mercury, amain positive elec- ,-.trode at the, remote end of the tube, said lamp being also provided with trunnions for amovemeht thereof about its longitudinal axis :1to separate said mercury electrode from said i v zogtsu'pplemental positive electrode; a support for said lamp adapted to maintain the same z-in a substantially horizontal position, such:

- support comprising a chamber inclosin the 11 auxiliary apparatus for operating the amp -'=ai1d members engaging the axial trunnions v:at'the ends of the lamp, and supporting said Elam in substantially horizontal position, in

- .-.:=eom ination with the operating circuits and inechanism for said lamp, comprising posi-,

u tive and ne ative'leads assing throu h said inclosing camber to t e main lea ing'in a m-s91 -interpos ed therein a ,ballast andan electro-- magnet in operative relation to-v an armature I? "mechanically connected. to rotatefthei'ilflmp" about its longitudinal axis, to causeithegmersi v cury electrode to flow out ofcontact withthe-j supplemental positive electrode, ashuntcirj-j cuit across themainleadsEofisaid v-'ci-rc i1it",'- 2; said 'shunt' circuit having seriallyi included 40 mental positive-electrode tort e mainnegative electrode ofthe lamp and --interdependent connections whereby'the axial movement of the lamp involves movement of the-current shiftingv device-to-sepa'rate' the "elec trodes thereof; said electromagnet being designed to have inductance, operating to serve W as starting inductance for efi'ecti ng' transfer-'- of current flow .from'the. supplemental-starting path to the mam lvaporathof the lamp, and also to serve as steel yinginductance .While the lam is in .o" ration. -Ej

Signed at ew Yor in thec'ountyiof New; York and State of NewYork this'19thfday' of December, A.D., 1906. a l

- i 3 v PERCY THOMArS. Witnesses: g 1, a

.WM.'H. 041 5 v d Tnos. H. BROWN; i

conductorsbf the-lamp, and having-serially I atv therein a resistance and a' current: shifting-.51.;-

device mounted for movment said shunt circuit being completed through the.' supple-' 

